This invention relates to a process for reducing CO and COS emissions from a fluidized bed reactor for chlorinating titanium containing material.
In such process, chlorine, particulate coke, and particulate titanium bearing material are fed to a fluidized bed reactor under conditions that chlorinate the titanium and many of the other metallic impurities. Gaseous titanium tetrachloride, other metallic chlorides such as iron chloride, CO, COS, CO.sub.2, and other gaseous products exit the fluidized bed reactor. The gaseous titanium tetrachloride produced can then be separated from the other metal chlorides and impurities and oxidized to titanium dioxide, which is useful as a white pigment, or further processed to produce titanium metal.
It would be desirable to reduce the amount of COS and CO emitted from the fluidized bed reactor because environmental requirements often restrict such materials to a low level. Emissions of COS and CO are often particularly a problem when the reactor is operated in the ferrous mode, i.e., at least 50 percent by volume of the iron chloride evolved from the fluidized bed reactor is ferrous chloride.
The following information is disclosed which may be of interest to this invention:
Reis, U.S. Pat. No. 4,961,911 discloses a process for reducing CO emissions from a fluidized bed reactor for chlorinating titanium containing material. The process consists of introducing chlorine above the surface of the fluidized bed while it is operated in the ferrous mode.
U.S. Pat. Nos. 2,790,703 and 3,526,477 disclose processes for chlorinating titanium containing material in a fluidized bed reactor. It is stated that titanium tetrachloride can be used to cool the reaction products from the fluidized bed.
U.S. Pat. Nos 3,883,636 and 3,591,333 also disclose processes for chlorinating titanium containing material in a fluidized bed reactor. The efficiency of chlorination is said to be improved by conducting it in the presence of compounds of chromium, lanthanum, vanadium, magnesium, calcium, strontium, barium, cadmium, and mixtures thereof.